Chromatographic parameters, pKa, and surface activity of a series of hydrochlorides of perhydroazepinylethyl esters of alkoxyphenylcarbamic acids and their relation to anaesthetic activity

1985 ◽  
Vol 50 (5) ◽  
pp. 1133-1140 ◽  
Author(s):  
Marie Blešová ◽  
Jozef Čižmárik ◽  
Mária Bachratá ◽  
Želmíra Bezáková ◽  
Alois Borovanský
Keyword(s):  
Biological Activity ◽  
Regression Analysis ◽  
Aqueous Solutions ◽  
Surface Activity ◽  
Local Anaesthetic ◽  
Chemical Properties ◽  
Surface Tensions ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Chromatographic Parameters

Hydrochlorides of perhydroazepinylethyl esters of alkoxyphenylcarbamic acids were separated by adsorption and partition TLC. The surface tensions, γ, of aqueous solutions of the compounds were measured and the values of pKa were determined. The relation between structure and physico-chemical properties has been confirmed by the dependences of RM and γ on the number of carbon atoms in the alkoxyl chain. Employing the method of regression analysis, the physico-chemical parameters of lipophilicity and the surface activity were correlated, and their effect on biological activity (relative local anaesthetic efficacy) has been assessed.

The effect of origin and physico-chemical properties on the kinetics of reduction of mixed NiO-Fe2O3 oxides with hydrogen

1986 ◽  
Vol 51 (10) ◽  
pp. 2098-2108 ◽  
Author(s):  
Milan Pospíšil ◽  
Jan Topinka
Keyword(s):  
Mixed Oxides ◽  
Mutual Influence ◽  
Spinel Phase ◽  
Chemical Properties ◽  
Inhibitory Effect ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Preliminary Annealing ◽  
Kinetics Of ◽  
Kinetics Of Reduction

We investigated the effect of origin and some physico-chemical parameters on the kinetics of reduction with hydrogen of two series of mixed NiO-Fe2O3 oxides differing by their composition, the character of their precursors (mixed crystalline nitrates and coprecipitated hydroxides) and their decomposition temperature.This effect manifested itself by different magnitudes of specific surfaces of the mixed oxides and coherent regions of present phases as well as by different oxidizing abilities of the surface and differences in morphology and phase composition of corresponding samples in both series investigated. Nonlinear or nonmonotonous composition dependences of physico-chemical parameters investigated point to a mutual influence of individual components, which is also a function of the system origin and which modifies its reactivity during its reduction with hydrogen. The kinetics of the reduction was studied thermogravimetrically at 320-410 °C. The reduction of oxides of the hydroxide origin is catalytically accelerated by primarily reduced nickel, whereas in corresponding samples of the nitrate series, the total NiO is bound to the spinel phase and the reduction is delayed. Experimental IR spectra, the effect of preliminary annealing and DTA of the mixed oxides point to an inhibitory effect of water, which is constitutionally bound in trace admixtures of the goethite phase, on the kinetics of reduction of samples in the hydroxide series.

scholarly journals Silver Nanoparticles Stabilized with Phosphorus-Containing Heterocyclic Surfactants: Synthesis, Physico-Chemical Properties, and Biological Activity Determination

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1883
Author(s):  
Martin Pisárčik ◽  
Miloš Lukáč ◽  
Josef Jampílek ◽  
František Bilka ◽  
Andrea Bilková ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Biological Activity ◽  
Zeta Potential ◽  
Chain Length ◽  
Alkyl Chain ◽  
Chemical Properties ◽  
Alkyl Chain Length ◽  
Microbial Pathogens ◽  
Physico Chemical ◽  
Phosphorus Containing

Phosphorus-containing heterocyclic cationic surfactants alkyldimethylphenylphospholium bromides with the alkyl chain length 14 to 18 carbon atoms were used for the stabilization of silver nanodispersions. Zeta potential of silver nanodispersions ranges from +35 to +70 mV, which indicates the formation of stable silver nanoparticles (AgNPs). Long-chain heptadecyl and octadecyl homologs of the surfactants series provided the most intensive stabilizing effect to AgNPs, resulting in high positive zeta potential values and smaller diameter of AgNPs in the range 50–60 nm. A comparison with non-heterocyclic alkyltrimethylphosphonium surfactants of the same alkyl chain length showed better stability and more positive zeta potential values for silver nanodispersions stabilized with heterocyclic phospholium surfactants. Investigations of biological activity of phospholium-capped AgNPs are represented by the studies of antimicrobial activity and cytotoxicity. While cytotoxicity results revealed an increased level of HepG2 cell growth inhibition as compared with the cytotoxicity level of silver-free surfactant solutions, no enhanced antimicrobial action of phospholium-capped AgNPs against microbial pathogens was observed. The comparison of cytotoxicity of AgNPs stabilized with various non-heterocyclic ammonium and phosphonium surfactants shows that AgNPs capped with heterocyclic alkyldimethylphenylphospholium and non-heterocyclic triphenyl-substituted phosphonium surfactants have the highest cytotoxicity among silver nanodispersions stabilized by the series of ammonium and phosphonium surfactants.

scholarly journals The Simultaneous Removal of Zinc and Cadmium from Multicomponent Aqueous Solutions by Their Sorption onto Selected Natural and Synthetic Zeolites

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 343 ◽  
Author(s):  
Bożena Kozera-Sucharda ◽  
Barbara Gworek ◽  
Igor Kondzielski
Keyword(s):  
Aqueous Solutions ◽  
Low Cost ◽  
Environmental Pollutants ◽  
Chemical Properties ◽  
Simultaneous Removal ◽  
Physico Chemical ◽  
Synthetic Zeolites ◽  
Sorption Mechanisms ◽  
Synthetic Aluminosilicate ◽  
Natural And Synthetic

Natural and synthetic aluminosilicate minerals, in particular zeolites, are considered to be very useful in remediation processes, such as purification of waters polluted with heavy metals. That is due to their unique and outstanding physico-chemical properties, rendering them highly efficient, low-cost, and environmentally friendly sorbents of various environmental pollutants. The aim of this study was to examine the sorption capacity of four selected zeolites: A natural zeolite and three synthetic zeolites (3A, 10A, and 13X), towards zinc and cadmium present in multicomponent aqueous solutions, in relation to identified sorption mechanisms. It was stated that synthetic zeolites 3A and 10A were the most efficient in simultaneous removal of zinc and cadmium from aqueous solutions. Additionally, zeolite 10A was demonstrated to be the mineral best coping with prolonged pollution of water with those elements. The mechanism of sorption identified for tested minerals was physisorption.

scholarly journals Effects of Physico-Chemical Parameters on Actinomycetes Communities during Composting of Agricultural Waste

2019 ◽  
Vol 11 (8) ◽  
pp. 2229
Author(s):  
Yuanping Li ◽  
Yanrong Chen ◽  
Yaoning Chen ◽  
Yanxin Wu ◽  
Chun Zhang ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Moisture Content ◽  
16S Rdna ◽  
Community Composition ◽  
Agricultural Waste ◽  
Chemical Parameters ◽  
16S Rdna Gene ◽  
Rdna Gene ◽  
Gene Abundance ◽  
Physico Chemical

The objective of this study was to investigate the influence of physico-chemical parameters on Actinomycetes communities and to prioritize those parameters that contributed to Actinomycetes community composition during the composting of agricultural waste. Denaturing gradient gel electrophoresis of polymerase chain reaction (PCR-DGGE) and redundancy analysis (RDA) were used to determine the relationships between those parameters and Actinomycetes community composition. Quantitative PCR (qPCR) and regression analysis were used to monitor the 16S rDNA copy numbers of Actinomycetes and to analyse the correlations between physico-chemical parameters and Actinomyces 16S rDNA gene abundance, respectively. The RDA results showed that moisture content, water soluble carbon (WSC) and pH (p < 0.05) made the main contributions to the temporal variations of Actinomycetes community composition. The output of the regression analysis indicated that moisture content (R2 = 0.407, p < 0.01) showed a negative linear relationship with the Actinomyces 16S rDNA gene abundance.

Permanent physico-chemical properties of extremely diluted aqueous solutions of homeopathic medicines

Homeopathy ◽  
2004 ◽  
Vol 93 (3) ◽  
pp. 144-150 ◽  
Author(s):  
V. Elia ◽  
S. Baiano ◽  
I. Duro ◽  
E. Napoli ◽  
M. Niccoli ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Extremely Diluted Aqueous Solutions

Mordanting of mercury on styrene-divinylbenzene copolymer beads from aqueous solutions

2007 ◽  
Vol 95 (5) ◽  
Author(s):  
Nasir Khalid ◽  
Saqib Ali ◽  
Arif Iqbal ◽  
Shujaat Ahmad
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Aqueous Media ◽  
Mercury Ions ◽  
Chemical Parameters ◽  
Radiotracer Technique ◽  
Physico Chemical ◽  
Styrene Divinylbenzene ◽  
Selection Of

The sorption of mercury ions from aqueous solutions on styrene-divinylbenzene copolymer beads (St-DVB) has been investigated for the decontamination of mercury from aqueous media. Various physico-chemical parameters, such as selection of appropriate electrolyte, contact time, amount of adsorbent, concentration of adsorbate, effect of diverse ions and temperature were optimized to simulate the best conditions which can be used to decontaminate mercury from aqueous media using St-DVB beads as an adsorbent. The radiotracer technique was used to determine the distribution of mercury. The highest adsorption was observed at 0.001 mol L

Preparation and Properties of Amide Surfactants

2012 ◽  
Vol 550-553 ◽  
pp. 99-102
Author(s):  
Bao Cai Xu ◽  
Gui Ju Zhang ◽  
Yun Xia Li ◽  
Lu Cui
Keyword(s):  
Surface Tension ◽  
Critical Micelle Concentration ◽  
Aqueous Solutions ◽  
Surface Activity ◽  
Surface Tensions ◽  
Equilibrium Surface ◽  
Minimum Surface Tension ◽  
Dilute Aqueous Solutions ◽  
Lipophilic Groups ◽  
Long Chain

Amide surfactants have modified structures with lipophilic groups connecting hydrophilic groups through amido bond. The preparation of three families of amide surfactants including long chain N-acyl sarcosinates, amidopropyl dimethyl hydroxypropyl sulfobetaines and lauryl amidopropyl trimethyl ammoniums were discussed. The study of the surface activity of these compounds by measuring the equilibrium surface tensions of their dilute aqueous solutions were described. The minimum surface tension and the critical micelle concentration values of these compounds are given.

scholarly journals Neurokinin Receptor Inhibitors: Fermentation, Isolation, Physico-chemical Properties, Structure and Biological Activity.

1997 ◽  
Vol 50 (12) ◽  
pp. 983-991 ◽  
Author(s):  
VINOD R. HEGDE ◽  
PING DAI ◽  
MIN CHU ◽  
MAHESH PATEL ◽  
ROBERT BRYANT ◽  
...  
Keyword(s):  
Biological Activity ◽  
Chemical Properties ◽  
Neurokinin Receptor ◽  
Physico Chemical

scholarly journals FR112123, a new oligopeptide antibiotic from Streptomyces viridochromogenes. Taxonomy, fermentation, isolation, physico-chemical properties, structure and biological activity.

1990 ◽  
Vol 43 (5) ◽  
pp. 449-455 ◽  
Author(s):  
AKIHIKO FUJIE ◽  
TOSHIRO IWAMOTO ◽  
NOBUHARU SHIGEMATSU ◽  
MASAMI EZAKI ◽  
MOTOHIRO HINO ◽  
...  
Keyword(s):  
Biological Activity ◽  
Chemical Properties ◽  
Physico Chemical
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